1.Role of BMP-2 in Osteoblast Differentiation.
Journal of Korean Society of Endocrinology 2001;16(4-5):393-400
No abstract available.
Osteoblasts*
2.MR findings of metastatic brain tumors.
Joong Mo AHN ; Kee Hyun CHANG ; Moon Hee HAN ; Sang Hoon CHA ; Jae Wook RYOO
Journal of the Korean Radiological Society 1993;29(3):355-361
The purpose of this study is to describe the magnetic resonance imaging (MR) findings of metastatic brain tumors with emphasis on the signal intensities of the lesion on MR. Thirty four patients with intracranial metastases were studies with MR imaging. The diagnosis was established on the basis of either brain biopsy or combination of brain MR findings and the presence of primary tumors. The primary tumors include lung cancer (n=18), breast cancer (n=3), stomach cancer (n=3), rectal cancer (n=1), renal cell carcinoma (n=1), hepatocellular carcinoma(n=1), ovarian cancer (n=1), thyroid cancer (n=1), melanoma (n=1) and unknown primary sites (n=4). The parenchymal lesions were solitary in 35% (12/34) and multiple in 65% (22/34). The size of the lesions was variable, ranging from several millimeters to 5cm in diameter. The corticomedullar junction of the cerebral heispheres was the most common location of the lesions (68%). The signal intensity of solid portion of the lesions was usually either isointense (44%) or hypointense (29%) on T1-weighted images, whereas it appeared in isointense (47%), hypointense (8%) or hyperintense (11%) on proton density-weighted or T2-weighted images. The remaining cases showed mixed signal intensities. The enhancement patterns were variable including nodular (<1cm) (6%), homogenous (19%), heterogeneous (10%), ring-like enhancement (22%) or mixed pattern(43%). The size of surrounding edema was larger than the tumor diameter in 76%. In conclusion, although there are no specific MR findings of intracranial metastasis except multiplicity, intracranial metastasis should be included in differential diagnosis with high priority, when a solitary mass showing isointensity on boty T1-and T2-weighted images with massive surrounding edema, especially in the corticomedullary junction of the cerebral hemispheres is encountered.
Biopsy
;
Brain Neoplasms*
;
Brain*
;
Breast Neoplasms
;
Carcinoma, Renal Cell
;
Cerebrum
;
Diagnosis
;
Diagnosis, Differential
;
Edema
;
Humans
;
Lung Neoplasms
;
Magnetic Resonance Imaging
;
Melanoma
;
Neoplasm Metastasis
;
Ovarian Neoplasms
;
Protons
;
Rectal Neoplasms
;
Stomach Neoplasms
;
Thyroid Neoplasms
3.MR findings of metastatic brain tumors.
Joong Mo AHN ; Kee Hyun CHANG ; Moon Hee HAN ; Sang Hoon CHA ; Jae Wook RYOO
Journal of the Korean Radiological Society 1993;29(3):355-361
The purpose of this study is to describe the magnetic resonance imaging (MR) findings of metastatic brain tumors with emphasis on the signal intensities of the lesion on MR. Thirty four patients with intracranial metastases were studies with MR imaging. The diagnosis was established on the basis of either brain biopsy or combination of brain MR findings and the presence of primary tumors. The primary tumors include lung cancer (n=18), breast cancer (n=3), stomach cancer (n=3), rectal cancer (n=1), renal cell carcinoma (n=1), hepatocellular carcinoma(n=1), ovarian cancer (n=1), thyroid cancer (n=1), melanoma (n=1) and unknown primary sites (n=4). The parenchymal lesions were solitary in 35% (12/34) and multiple in 65% (22/34). The size of the lesions was variable, ranging from several millimeters to 5cm in diameter. The corticomedullar junction of the cerebral heispheres was the most common location of the lesions (68%). The signal intensity of solid portion of the lesions was usually either isointense (44%) or hypointense (29%) on T1-weighted images, whereas it appeared in isointense (47%), hypointense (8%) or hyperintense (11%) on proton density-weighted or T2-weighted images. The remaining cases showed mixed signal intensities. The enhancement patterns were variable including nodular (<1cm) (6%), homogenous (19%), heterogeneous (10%), ring-like enhancement (22%) or mixed pattern(43%). The size of surrounding edema was larger than the tumor diameter in 76%. In conclusion, although there are no specific MR findings of intracranial metastasis except multiplicity, intracranial metastasis should be included in differential diagnosis with high priority, when a solitary mass showing isointensity on boty T1-and T2-weighted images with massive surrounding edema, especially in the corticomedullary junction of the cerebral hemispheres is encountered.
Biopsy
;
Brain Neoplasms*
;
Brain*
;
Breast Neoplasms
;
Carcinoma, Renal Cell
;
Cerebrum
;
Diagnosis
;
Diagnosis, Differential
;
Edema
;
Humans
;
Lung Neoplasms
;
Magnetic Resonance Imaging
;
Melanoma
;
Neoplasm Metastasis
;
Ovarian Neoplasms
;
Protons
;
Rectal Neoplasms
;
Stomach Neoplasms
;
Thyroid Neoplasms
5.Localization of bone matrix gene mrna in regenerating bone tissue during the guided bone regeneration
Chang Kon LEE ; Hyun Mo RYOO ; Hong In SHIN
Journal of the Korean Association of Maxillofacial Plastic and Reconstructive Surgeons 1999;21(3):240-248
Animals
;
Bone and Bones
;
Bone Marrow
;
Bone Marrow Cells
;
Bone Matrix
;
Bone Regeneration
;
Confined Spaces
;
Connective Tissue
;
Femur
;
In Situ Hybridization
;
Macrophages
;
Membranes
;
Osteoblasts
;
Osteocalcin
;
Osteoclasts
;
Osteocytes
;
Osteogenesis
;
Osteonectin
;
Osteopontin
;
Polytetrafluoroethylene
;
Porifera
;
Rats
;
RNA, Messenger
6.Dynamics of gingival crevicular fluid volume and enzyme activities after application of orthodontic force.
Ae Ree KANG ; Hyun Mo RYOO ; Jae Hyun SUNG
Korean Journal of Orthodontics 1989;19(3):137-145
The aim of this investigation was to study the effect of orthodontic force on the flow of gingival crevicular fluid and activities of arylsulfatase and brta-glucuronidase in crevicular fluid. The material consisted of 12 persons between the ages of 13 years and 22 years and all were categorized Class I, 4-4 extraction cases Crevicular fluids were sampled from distal crevis of each canine before treatment (phase 1), after bracketing (phase 2), after application of force (phase 3) and after run out of orthodontic force (phase 4). Crevicular fluid flow did not show any significant changes during the period of treatment. The activities of arylsulfatase increased significantly after setting of orthodontic appliance without application of force, but did not show any significant difference after application of force. The activities of beta-glucuronidase increased significantly after application of orthodontic force and decreased with force deminished. These indicated that beta-glucuronidase was good indicator of bone remodelling resulted from initial orthodontic force.
Gingival Crevicular Fluid*
;
Glucuronidase
;
Humans
;
Orthodontic Appliances
7.Role of Transcription Factors in Bone and Vascular Mineralization.
Journal of Korean Society of Endocrinology 2005;20(6):589-596
No Abstract available.
Transcription Factors*
8.A Novel Osteogenic Activity of Suberoylanilide Hydroxamic Acid is Synergized by BMP-2.
Zang Hee LEE ; Hyun Jung KIM ; Hyun Mo RYOO
Journal of Bone Metabolism 2015;22(2):51-56
BACKGROUND: Many histone deacetylase (HDAC) inhibitors are well recognized as potential anti-cancer drugs. Inhibition of HDACs induces temporal transcription or epigenetic control, thus regulating many different biological responses. Here, we investigated the osteogenic effect of the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA; vorinostat). METHODS: The effects of SAHA on osteoblast differentiation were examined in the 6XOSE-Luc reporter assay for determination of runt-related transcription factor 2 (Runx2) activity and alkaline phosphatase (ALP) activity and in an immunoprecipitation assay to determine the Runx2 acetylation state. The osteogenic activity of SAHA in vivo was studied in and receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoporotic mouse model. RESULTS: SAHA increased the transcriptional activity of Runx2 in a dose-dependent manner in the 6XOSE-Luc reporter assay. SAHA by itself was unable to induce ALP activity; however, SAHA enhanced ALP activity induced by bone morphogenetic protein-2 (BMP-2). The degree of acetylation of Runx2 was increased with SAHA treatment, which suggests that the increase in Runx2 transcriptional activity might be dependent on stabilization by acetylation. Also, SAHA successfully reversed soluble RANKL-induced osteoporotic bone loss. CONCLUSIONS: Our study shows an intriguing osteogenic potential of SAHA in a BMP-2-dependent manner and suggests that SAHA could be used at lower doses along with BMP-2 to treat osteoporosis.
Acetylation
;
Alkaline Phosphatase
;
Animals
;
Bone Morphogenetic Protein 2
;
Epigenomics
;
Histone Deacetylase Inhibitors
;
Histone Deacetylases
;
Hydroxamic Acids*
;
Immunoprecipitation
;
Mice
;
Osteoblasts
;
Osteogenesis
;
Osteoporosis
;
RANK Ligand
;
Transcription Factors
9.Osteoblast differentiation of human bone marrow stromal cells (hBMSC) according to age for bone tissue engineering.
Gin Ah SONG ; Hyun Mo RYOO ; Jin Young CHOI
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2010;36(4):243-249
Tissue engineered bone (TEB) can replace an autogenous bone graft requiring an secondary operation site as well as avoid complications like inflammation or infection from xenogenic or synthetic bone graft. Adult mesenchymal stem cells (MSC) for TEB are considered to have various ranges of differentiation capacity or multipotency by the donor site and age. This study examined the effect of age on proliferation capacity, differentiation capacity and bone morphogenetic protein-2 (BMP-2) responsiveness of human bone marrow stromal cells (hBMSC) according to the age. In addition, to evaluate the effect on enhancement for osteoblast differentiation, the hBMSC were treated with Trichostatin A (TSA) and 5-Azacitidine (5-AZC) which was HDAC inhibitors and methyltransferase inhibitors respectively affecting chromatin remodeling temporarily and reversibly. The young and old group of hBMSC obtained from the iliac crest from total 9 healthy patients, showed similar proliferation capacity. Cell surface markers such as CD34, CD45, CD90 and CD105 showed uniform expression regardless of age. However, the young group showed more prominent transdifferentiation capacity with adipogenic differentiation. The osteoblast differentiation capacity or BMP responsiveness was low and similar between young and old group. TSA and 5-AZC showed potential for enhancing the BMP effect on osteoblast differentiation by increasing the expression level of osteogenic master gene, such as DLX5, ALP. More study will be needed to determine the positive effect of the reversible function of HDAC inhibitors or methyltransferase inhibitors on enhancing the low osteoblast differentiation capacity of hBMSC.
Adult
;
Aging
;
Bone and Bones
;
Bone Marrow
;
Chromatin Assembly and Disassembly
;
Durapatite
;
Histone Deacetylase Inhibitors
;
Humans
;
Hydroxamic Acids
;
Inflammation
;
Mesenchymal Stromal Cells
;
Osteoblasts
;
Tissue Donors
;
Transplants
10.C-erbB-2 Protein Expression and Correlation in Sera and Tumors of Non-Small Cell Lung Cancer Patients.
Hun Mo RYOO ; Sang Yeop LEE ; Kyung Hee LEE ; Myung Soo HYUN ; Mi Jin KIM
Journal of the Korean Cancer Association 2000;32(6):1100-1108
PURPOSE: We have examined the expression of c-erbB-2 oncogene in sera and tissues of non-small cell lung cancer patients. MATERIALS AND METHODS: Serum levels of c-erbB-2 protein were measured by an enzyme im munoassay in 55 patients with non-small cell lung cancer. Sera from patients with surgical therapy were evaluated again after surgery. Immunohistochemical staining was performed in 47 of these tumors. RESULTS: Elevated levels (> or =45 U/mL, control mean 2SD) were observed in 15% of 55 non-small cell lung cancer patients, as compared with none of control subjects (p<0.05). The incidence of elevated level was higher in the adenocarcinoma than squamous cell carcinoma (22% vs 4%, p<0.01). The serum levels of c-erbB-2 protein decreased significantly after surgical tumor ablation (p<0.01). Tissue overexpression was obtained in 23/47 cases (49%). The incidence of c-erbB-2 overexpression was higher in the adenocarcinoma (73% vs 29%, p<0.005). No relationship was found between c-erbB-2 protein expression in serum and tumor tissue and clinicopathologic feature. Elevated serum c-erbB-2 levels predicted tissue overexpression with sensitivity 30% and specificity 96%. There was relationship between serum level and expression in tumor tissue of c-erbB-2 protein. CONCLUSION: Serum and tissue levels of c-erbB-2 correlate in patients with non-small cell carcinoma. Serum c-erbB-2 protein may be a useful indicator of tumor burden in patients with non-small cell lung cancer.
Adenocarcinoma
;
Carcinoma, Non-Small-Cell Lung*
;
Carcinoma, Squamous Cell
;
Humans
;
Incidence
;
Oncogenes
;
Receptor, erbB-2*
;
Sensitivity and Specificity
;
Tumor Burden